fix(boards): 修复xpython下变量名大小写不敏感

boards/default_src/python/others/names.js

@@ -117,7 +117,7 @@ class Names {
                 name = varName;
             }
         }
-        var normalized = name.toLowerCase() + '_' + type;
+        var normalized = name + '_' + type;
 
         var isVarType = type == Variables.NAME_TYPE ||
             type == Names.DEVELOPER_VARIABLE_TYPE;

boards/default_src/python/others/variables.js

@@ -56,7 +56,7 @@ Variables.allVariables = function (root) {
             var varName = blockVariables[y];
             // Variable name may be null if the block is only half-built.
             if (varName) {
-                variableHash[varName.toLowerCase()] = varName;
+                variableHash[varName] = varName;
             }
         }
     }
@@ -215,7 +215,7 @@ Variables.generateUniqueName = function (workspace) {
         while (!newName) {
             var inUse = false;
             for (var i = 0; i < variableList.length; i++) {
-                if (variableList[i].toLowerCase() == potName) {
+                if (variableList[i] == potName) {
                     // This potential name is already used.
                     inUse = true;
                     break;